PROJECT SUMMARY/ABSTRACT There are more than 400,000 adolescent and young adult female (AYA-F) cancer survivors currently living in the US, and the potential loss of fertility has been described as one of the most distressing aspects of survivorship. The majority of AYA-Fs want to have children in the future. Four factors are critical in understanding how fertility issues play out in AYA-F survivorship: 1) the majority of patients do not preserve their fertility prior to treatment; 2) many will maintain reproductive potential after treatment but will be at risk for premature menopause; 3) lack of information, uncertainty, and distress lead to incorrect assumptions or avoidance of addressing fertility in survivorship; and 4) family-building is often not a focus as survivors prioritize normality and pursue education, careers, and develop intimate relationships in the same timeline as their peers The proposed study will be the first to explore how AYA-Fs make decisions about future family-building and their decision support needs, preferences, and perceived barriers. The goals of this study will be (1) to develop the first theoretically driven, evidence-based decision aid tool tailored to AYA-Fs making decisions about future family-building, and (2) to comprehensively evaluate AYA-Fs' decision support needs, preferences, and perceived barriers. We will recruit AYA-Fs (N=120) who completed gonadotoxic treatment, are pre- menopausal with no history of fertility preservation, and who want future children or are unsure about their reproductive plans. AYA-Fs will first complete a set of quantitative measures assessing fertility-related cognitions, emotions, and decision processes. We will conduct in-depth semi-structured interviews with a subset of participants (N=24-30) and use thematic content analysis to explore themes of decision-making and decision support needs, preferences, and perceived barriers. Qualitative themes will be validated with quantitative measures and will be used to identify whether AYA-Fs at-risk for high levels of decision distress may be identified. The need for additional support services will be explored and findings will inform the development of a large decision support intervention design. The proposed study is the first step in developing the first theoretically driven, evidence-based intervention to help AYA-Fs make informed, values-based decisions about their reproductive future, thereby avoid the potential negative psychosocial consequences of infertility.